The fill temperature rises above 70ºC and proteins are gradually denatured. High fill temperatures for defined time period cause inactivation of present bacteria and pathogenic organisms (viruses, bacteria, leaven, mould, protozoons, and worms). This process is called thermofilic aerobic stabilization and hygienization of the fill. Due to high temperature the number of microorganisms is decreasing and weed seeds loose their germinating capacity. It takes 48 - 96 hours.
After the thermophilic aerobic fermentation is finished the fill is stabilized and hygienized. As its qualities have been essentially changed it is further on called fermentate. It can be used as compost for agrotechnical use or compost for energetic use (biofuel).